SJF Preemptive algorithm problem

Prob. For the following jobs calculate the turnaround time, waiting time using RR (time quantum=1), SJF (pre-emptive) scheduling algorithms.

Jobs	CPU Burst Time	Arrival Time
1	10	0.0
2	2	3.0
3	1	4.0
4	4	5.0

Ans.

SJF (pre-emptive) scheduling algorithms:

SJF (Preemptive): Average waiting time calculation

SJF(Premptive): Averrage turnaround time calculation

SJF(Preemptive): Average response time calculation

Operating Systems:

EasyExamNotes.com covered following topics in Operating Systems.

• Introduction to Operating Systems
• Function of OS
• Evolution of OS 
• Different Types of OS
• Desirable Characteristics and features of an OS
• Operating Systems Services
• Utility Programs
• System Calls
• File Systems: File Concept
• Contiguous disk space allocation met
• Directory Structures
• Disk Scheduling Algorithms
• FCFS Disk Scheduling Algorithms
• SSTF Disk Scheduling Algorithms
• SCAN Disk Scheduling Algorithms
• CSCAN Disk Scheduling Algorithms
• LOOK Disk Scheduling Algorithms
• CLOOK Disk Scheduling Algorithms.
• CPU Scheduling
• CPU Scheduling Concepts
• CPU Scheduling Algorithms
• FCFS CPU scheduling algorithm
• Nonpreemptive SJF CPU scheduling algorithm
• Preemptive SJF (SRTF) CPU scheduling algorithm
• Round Robin CPU scheduling algorithm
• Process Concept
• Process State Diagram
• Types of Schedulers
• System calls for Process Management
• Multiple Processor Scheduling
• Concept of Threads
• Memory Management
• Different Memory Management Techniques
• Swapping
• Segmentation
• Paging
• Paging vs Swapping
• Paging vs Segmentation
• Overlay in memory management
• FCFS page replacement algorithm
• LRU page replacement algorithm 
• Optimal page replacement algorithm
• Critical Section Problem
• Deadlock Avoidance, Recovery

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